Microsoft Exchange Server 2010 has enhanced language support for
both servers and clients. This topic provides information about
language packs, including the specific languages that are supported
for both servers and clients in Exchange 2010.

Exchange 2010
Language Packs

An Exchange 2010 language pack contains the necessary
resources for a supported Exchange language. Language packs are
installed during installation of Exchange 2010. Client and server
language packs come grouped into a single bundle containing both
client and server resource and support files. There are no
performance issues with installing all the languages because
they're just stored when not in use.

For organizations that have users in multiple
languages, we recommend that you do the following:

On Unified Messaging (UM) servers, only install the UM language
pack that you need for your organization. The addition of extra UM
language packs introduces more processing when the server builds
speech grammar for each language.

Pre-recorded prompts, for example, "After the tone, please
record your message. When you’ve finished recording, hang up, or
press the # key for more options." in the language of the UM
language pack.

Grammar files that are used by a Unified Messaging server to
look up the names of specific users in the directory in the
language of the UM language pack.

Text-to-Speech (TTS) translation so that content (for example,
e-mail, calendar, or contact information) can be read to callers in
the language of the UM language pack.

Support for ASR, which allows callers to interact with Unified
Messaging using the Voice User Interface (VUI) in the language of
the UM language pack.

Support for Voice Mail Preview, which allows users to read the
transcript of voice mail messages in a specific language from
within a supported e-mail client such as Microsoft Outlook or
Outlook Web App.

The U.S. English (en-US) language pack contains UM
prompts, TTS, ASR, and Voice Mail Preview support for this
language.

Important:

The UM language pack must only be installed as an add-in to
Exchange 2010 Unified Messaging.